It is known that the human wrist varies in diameter as a function of the ambient temperature. During the warm season its diameter increases, while during the cool season this diameter decreases. A bracelet encircling the wrist must therefore be able to be adjusted as a function of these differences in diameter if one wishes, in the circumstances mentioned above, to prevent the bracelet hanging from or pinching the wrist.
Wristlets made of leather may have a sufficient number of holes to facilitate this adjustment. Indeed, one chooses the appropriate hole to be received by the tongue of the buckle in order to fit the wristlet correctly. On the other hand, if one is dealing with a bracelet formed of articulated links, this choice is no longer possible and one has to be satisfied with a length adjustment which is made once and for all when the bracelet is purchased. Further, at the time of this purchase, one is limited to an adjustment which is no more precise than that of the length of a link. In order to overcome this disadvantage and in the event that the chain link bracelet comprises for example a folding type clasp, a solution to this problem has already been proposed, a solution is explained for example in patent application EP-A-0 350 785.
In this document, the clasp comprises a first element carrying a hook and a second element under which is arranged a spring catch attached to a push-piece. The second element is provided with an opening which reveals two identical holes arranged side by side in the longitudinal direction of the bracelet. The hook may be locked as required into the first or the second hole according to whether one wishes the bracelet to be tightly or more loosely wound around the wrist. In a closed position the catch of the hook is placed under the spring catch. In order to open the clasp, one presses the push-piece. This device enables the length of the bracelet to be lengthened or shortened by an amount shorter than the length of a link.
Other clasps are provided with systems producing the same effect. For example, patent applications CH-A-669 501, DE-A-2 852 482 and FR-A-2 058 819 all use a system provided with sliding racks and clicks.
Thus all the proposed fine adjustment systems known to the applicant are connected to a clasp which is sometimes complicated to manufacture. In order to overcome these disadvantages, the invention proposes an adjustable link which is independent from the clasp.